High-frequency filter and communication device module

Abstract

A signal transmission cable including a high-Q value band-elimination filter includes a first signal line conductor pattern including a first capacitor conductor portion and an inductor conductor portion on a first base layer. The first capacitor conductor portion includes a flat conductor, and the inductor conductor portion has a spiral shape. A second signal line conductor pattern including a second capacitor conductor portion is provided on a second base layer. The inductor conductor portion constitutes an inductor, and the first and second capacitor conductor portions and the first base layer constitute a capacitor. The inductor and the capacitor are connected in parallel by transmission conductor portions on the first and second base layers and an interlayer-connector conductor on the first base layer.

What is claimed is: 
     
       1. A high-frequency filter comprising:
 a signal transmission line that connects a first external connection terminal and a second external connection terminal; 
 a flat base body in which the signal transmission line is defined by a conductor pattern; and 
 a filter that is connected between the first external connection terminal and the second external connection terminal by the signal transmission line and includes an inductor and a capacitor provided in or on the flat base body; wherein: 
 the flat base body includes a multilayer structure including a stack of a plurality of base layers including a first layer and a second layer; 
 the inductor consists of a plurality of line conductor patterns on the plurality of base layers and a plurality of interlayer connection conductors in at least one of the plurality of base layers; 
 the plurality of line conductor patterns are wound along an outer periphery of the plurality of base layers; 
 the plurality of interlayer connection conductors are respectively connected to the plurality of line conductor patterns; 
 the capacitor includes portions of the plurality of line conductor patterns, facing each other in a stacking direction of the multilayer structure; 
 the plurality of line conductor patterns include a first route disposed on a side in a planer direction parallel to a principal surface of the plurality of base layers with reference to a straight line from the first external connection terminal to the second external connection terminal, and a second route disposed on another side in the planer direction with reference to the straight line; 
 the first route and the second route are connected in parallel between the first external connection terminal and the second external connection terminal; 
 the first route includes a first portion provided on the first layer and a second portion provided on the second layer, the first portion and the second portion facing each other so as to extend in parallel; 
 the first portion and the second portion are connected in parallel by the plurality of interlayer connection conductors at positions which include a middle position in a direction in which the first portion and the second portion extend; 
 the second route includes a third portion and a fourth portion provided on the first layer, and a fifth portion and a sixth portion provided on the second layer, the third portion and the fourth portion are not physically connected to each other in the second route, the fifth portion and the sixth portion are not physically connected to each other in the second route; 
 the third portion and the fifth portion partially face each other in the stacking direction and are connected in parallel by at least one of the plurality of interlayer connection conductors at a middle position of the third portion and the fifth portion in a direction in which the third portion and the fifth portion extend; 
 the fourth portion and the sixth portion partially face each other in the stacking direction and are connected in parallel by at least one of the plurality of interlayer connection conductors at a middle position of the fourth portion and the sixth portion in a direction in which the fourth portion and the sixth portion extend; and 
 the third portion and the sixth portion partially face each other in the stacking direction to constitute the capacitor. 
 
     
     
       2. The high-frequency filter according to  claim 1 , wherein
 the base body is flexible. 
 
     
     
       3. A communication device module comprising:
 a high-frequency filter according to  claim 1 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       4. The high-frequency filter according to  claim 2 , wherein
 the base body includes a bent portion between a portion of the first external connection terminal and a portion of the second external connection terminal. 
 
     
     
       5. A communication device module comprising:
 a high-frequency filter according to  claim 4 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       6. The high-frequency filter according to  claim 4 , wherein
 at least one of the first external connection terminal and the second external connection terminal includes a connector member that establishes an electrical connection with an external circuit by connecting each other mechanically. 
 
     
     
       7. A communication device module comprising:
 a high-frequency filter according to  claim 6 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       8. The high-frequency filter according to  claim 2 , wherein
 at least one of the first external connection terminal and the second external connection terminal includes a connector member that establishes an electrical connection with an external circuit by connecting each other mechanically. 
 
     
     
       9. A communication device module comprising:
 a high-frequency filter according to  claim 8 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       10. A communication device module comprising:
 a high-frequency filter according to  claim 2 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       11. The high-frequency filter according to  claim 1 , wherein
 the base body includes a bent portion between a portion of the first external connection terminal and a portion of the second external connection terminal. 
 
     
     
       12. A communication device module comprising:
 a high-frequency filter according to  claim 11 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       13. The high-frequency filter according to  claim 11 , wherein
 at least one of the first external connection terminal and the second external connection terminal includes a connector member that establishes an electrical connection with an external circuit by connecting each other mechanically. 
 
     
     
       14. A communication device module comprising:
 a high-frequency filter according to  claim 13 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal. 
 
     
     
       15. The high-frequency filter according to  claim 1 , wherein
 at least one of the first external connection terminal and the second external connection terminal includes a connector member that establishes an electrical connection with an external circuit by connecting each other mechanically. 
 
     
     
       16. A communication device module comprising:
 a high-frequency filter according to  claim 15 ; 
 an antenna board connected to the first external connection terminal; and 
 a front end board connected to the second external connection terminal.